Byssinosis, a common and crippling disease among several categories of textile workers, is characterized by symptoms of bronchoconstriction on first working days after absence from work, and by the development of severe and irreversible ventilatory insufficiency after many years of exposure to various textile dusts. A better understanding of physiological and pharmacological mechanisms of the action of textile dusts on the lungs is urgently needed now that byssinosis is increasingly being recognized as a significant health problem in the cotton textile industry in the United States. This proposal includes chemical, biochemical, pharmacological, epidemiological and other studies designed to increase our understanding of the nature of the disease and of the methods that can be used to control and prevent it. These include: (1) determination of the chemical nature of the pharmacological agent(s) in textile dust which cause bronchoconstriction in man; (2) investigations of the mechanisms by which textile dusts affect the airways and the lungs; (3) study of the factors that determine the interindividual variability of airway responses to textile dust; (4) assessment of the importance of disabling respiratory disease among textile workers as a public health problem. Data on the prevalence of disabling lung disease among retired textile workers are crucial (a) to determine how often early byssinosis progresses to disabling disease, (b) to determine the time course of the progression of the disease, and (c) to provide baseline data for assessment of the economical importance of disabling respiratory disease among textile workers. We are also planning follow-up studies of textile workers who were seen in previous field investigations in the industry, and we will (5) assess the efficacy of drugs which may ameliorate airway obstruction in textile workers. An integral part of our program will be (6) the application of our research results in programs designed for the prevention and control of respiratory disease in textile workers.